The present invention relates to hair spray compositions and, particularly, to hair spray compositions which are suitable for aerosol application.
Substances which are suitable candidates for use as a hair spray composition must fulfill a number of requirements. They must form glossy, clear films which are capable of adhering to the hair fiber. Further, they must have good solubility in the solvent media with which they are associated. The film which is formed on the hair must be sufficiently flexible to hold the hair in place permanently despite the usual agitation attributable to wind and movement of the head yet the film must be sufficiently stiff to allow the hair to be combable without collapsing.
In addition, substances utilized must form a film which, on one hand, must be water-soluble or at least capable of swelling under the action of water to be removable by ordinary shampooing methods and which, on the other hand, must be substantially uneffected by water vapor even at high relative humidity.
It is clear that the requirements set forth for hair spray compositions have built within them certain diametrically opposed properties which make a large number of apparently potential compositions unsuitable for such use.
For example, many polymer compositions heretofore used have the desired solubility properties but are highly hygroscopic and, therefore, give the hair a sticky feel at relatively high humidity. Some polymers which are substantially non-hygroscopic exhibit unsatisfactory solution properties. Still other compositions have good hygroscopicity and solution properties but are difficult to remove from the hair which, therefore, causes an undesired build-up of the composition on the hair.
Further, hair spray compositions are presently commonly applied to the hair by aerosol technique. Aqueous compositions are generally excluded from being packaged with conventional aerosol containers and propellants due to container corrosion problems caused by such compositions as well as stability problems of propellants, especially halogenated hydrocarbons, with the water of the composition.
Polymeric systems which have been previously proposed include carboxy-containing copolymers such as disclosed in U.S. Pat. Nos. 2,723,248 and 3,723,616. These polymers are made washable from the hair by neutralizing the polymer with a lower molecular weight hydroxy-containing amine, such as diethanolamine or aminomethyl propanediol. Such products have increased moisture sensitivity and, thus, are of little aid in retaining the shape of the hair during periods of high humidity. U.S. Pat. No. 3,850,178 is also directed to hair setting compositions which utilize carboxy-containing resins in combination with a complex formed from a polyvalent metal compound and an alkaline compound. The highly alkaline pH of the composition can be harmful to the hair, possibly causing degradation thereto. Further, the composition requires the use of an aqueous carrier which effectively restricts the utility of the composition to non-aerosol applications due to corrosion and stability problems.